1. Field of the Invention
The present invention relates to a method and cosmetic abrasive scrubbing pad for scrubbing and removing detritus (such as dead skin or dander), soil and other foreign matter from the epidermis.
2. Discussion of the Prior Art
The skin is an organ separating the inside of the body from the outside world, covers twelve to twenty square feet in area and accounts for 12% of body weight, on average. It is composed of three integrated layers, the epidermis, dermis and subcutis, the layers are referred to as "over skin", "skin" and "under skin". The epidermis is the outermost layer, forming an overall protective covering for the entire body and never more than 0.125 inches thick. At the bottom of the epidermis lies the basal layer in which cell division generates new cells daily. The rate of multiplication for new cells depends on the body's available energy and, in a cycle lasting approximately 27 days, new cells move upwardly through the epidermis, gradually changing from the soft columnar cells of the basal layer from which they are eventually shed. The skin cells are attached to one another by plaques called desmosomes and ascend toward the surface of the over skin in a continuous, impermeable layer. The stratum corneum or horny corneal layer is the outermost part of the epidermis and is comprised of dead epidermal cells averaging 20 cells deep, creating a durable, protective outer barrier for the layers beneath which is resistant to salt and water, further protecting living cells from the damaging effects of excessive dehydration. Excess dead skin cells and sebum accumulate upon the horny corneal layer of the epidermis.
Skin may appear clean and vacant to the naked eye but the number of living organisms on a person's skin is estimated to number in the billions. The flora and fauna of the skin are substantially permanent residents and vary from one region of the body to another, since differing populations of bacteria, mites and yeasts have adapted to specific environments. The dry expanse of the forearm, the dense tangle of the scalp and the oily surface of the nose all harbor particular species. The largest community of the skin's residents are bacteria, usually acquired at birth. Bacteria spreads from person to person both by contact and by constant shedding of dead skin cells. Daily skin loss prevents many would-be colonists from gaining a foothold on the skin. The skin also presents an acidic mantle that deters certain types of bacteria. When the skin's bacteria break down, sebum (fatty acids that increase the skins acidity) are produced. Bacteria thrive in moist areas, so the dryness of the skin may account for part of its resistance to bacterial infections.
The skin plays a prominent role in maintaining the body's temperature. The set point temperature, 98.6.degree. F., is kept in delicate balance; the system is so delicate that if the core temperature varies by 1.5.degree. F. the body's metabolism is altered by about 20%. When the body heat shifts slightly from the set point, the skin's temperature regulation mechanisms quickly restore the proper temperature. The skin achieves this regulation largely by controlling the amount of heat lost. To do so, the skin works in concert with the hypothalamus, a cluster of nerve cells at the center of the brain. Specialized regions of that hypothalamus contain heat sensitive and cold sensitive cells responsive to changes in blood temperature by increasing the number of nerve impulses they transmit. On receiving the hypothalamus commands, the skin hastens to make the appropriate adjustments, restricting blood flow to reduce heat loss or increasing blood flow and activating sweat glands to shed heat. The skin also includes heat receptors and cold receptors which play an important part in detecting temperature changes and permitting precise control of body temperature.
Dirty, unhealthful skin with clogged pores and accumulated detritus such as excess dead skin will not perform the skin's functions as well as healthy, clean skin. Skin care is usually considered to be of paramount importance in maintaining healthy skin and a youthful appearance. The cosmetics industry has devoted considerable resources to the problems of women and men seeking healthy or youthful skin. With age, most people observe that skin becomes increasingly dryer and less elastic and dead skin, dander, flakes and other detritus tend to accumulate on the skin surface (i.e., the over skin or outer epidermis). Accumulated detritus such as dead skin and oxidized sebaceous oil can give rise to a number of skin problems such as formation of comedos or blackheads, resulting in clogged pores. In the prior art, a number of devices have been proposed for scraping, scrubbing or otherwise exfoliating the skin. For example, the exfoliator disc of U.S. Pat. No. 4,438,767, to Nelson, includes a flat circular blade with a circumferential scraping edge for scraping dead skin tissue away. The Nelson scraper is dragged at a selected angle with a selected force to remove dead skin tissue. Being circular, the scraping edge is concave out at a given radius and presents uneven scraping pressure for those parts of the body not having a convex contour with the given radius. Thus, someone using the Nelson scraper cannot apply uniform scraping pressure over even a small area of the body.
Many of the devices of the prior art are intended for use solely by medical professionals such as dermatologists who perform a process known as dermabrasion, wherein rigid abrading stones and other abrading devices are manipulated to remove skin. Rigid abrading devices are not well suited for removing skin from contoured areas such as the elbow or heel and so, even in the hands of a skilled dermatologist, skin "burns" can occur. U.S. Pat. No. 4,459,987, to Pangburn, discloses a flexible abrasive pad intended to permit a dermatologist to remove skin while avoiding creation of skin burns and including a flexible sheet of silicone polymer carrying abrasive particulate and a layer of reticulated, resiliently compressible foam, for light dermabrasion. The Pangburn pad has pumice particulate cured into a silicon sheet and so dead skin or the like will tend to clog and fill the pad as sandpaper clogs when sanding wood. The Pangburn pad must also be used with a selected amount of pressure since the silicon is flexible but transmits the pressure applied directly to the surface being abraded. A dermatologist using the Pangburn pad can rely on his or her professional judgement in deciding how much pressure to apply, when the pad should be cleaned and with what, to avoid problems of skin burn, clogging and filling; lay persons, however, may not be able to use the pad as safely as a dermatologist.
There is a need, therefore, for a method and cosmetic apparatus for safely removing detritus (such as excess dead skin cells or dander), soil or other foreign matter from the epidermis, while overcoming the problems with the prior art as described above.